| |||||||||||||
when things are exposed to userspace, the bock based api is needed morewhen things are exposed to userspace, the bock based api is needed morePosted Jan 25, 2013 18:29 UTC (Fri) by zlynx (subscriber, #2285)In reply to: when things are exposed to userspace, the bock based api is needed more by dlang Parent article: GPIO in the kernel: future directions
The timing and preemption problem is why I used SCHED_FIFO when I wrote a user-space front-panel LCD driver for an embedded system, long ago.
The program runs SCHED_OTHER as normal, then escalates into SCHED_FIFO at prio 95 (something like that) to program the data ports, then falls back.
I know that kernel interrupts and similar things may interfere but it was never a problem in practice. The LCD's timing requirements were not overly strict, just that you couldn't go away and ignore it for tens of milliseconds.
(Log in to post comments)
when things are exposed to userspace, the bock based api is needed more Posted Jan 25, 2013 19:59 UTC (Fri) by dlang (✭ supporter ✭, #313) [Link]
am I correct in thinking that the grouping capability would ease things and make it so that this could be done without SCHED_FIFO?
|
|||||||||||||